Textures black after importing obj file
You need to add a light to see (if everything is dark you can only see black).

You simply imported the mesh, there is nothing else in your scene. You have no lights in your scene. You (kind of) need a light to see your object.

For just a simple test render, or so you can see your object, just add a few lamps. If you add just one then the side in the shadow will still be black.